Non-load starting device and method for variable hydraulic pump

Abstract

The invention relates to a non-load starting device and method for a variable hydraulic pump and belongs to the fields of fluid transmission and control. The non-load starting device for the variable hydraulic pump comprises the variable hydraulic pump and a little-channel direction control valve, wherein the variable hydraulic pump is provided with a control port X, and the direction control valve is used for performing unloading on an X port oil path of a variable control device of the variable hydraulic pump. During starting, unloading of the X port oil path of the variable control device is achieved through the direction control valve, so the displacement of the variable hydraulic pump can return to zero quickly. In the process of converting a stating state into a normal working state, the X port oil path of the variable control device can be in a non-load state through the control action of the direction control valve, and therefore the variable hydraulic pump can enter the normal working state. The invention further discloses a non-load starting method for the variable hydraulic pump. The non-load starting device is simple and reliable in structure, small in system impact pressure, free of flow overflowing power loss and suitable for non-load starting of variable hydraulic pumps with large displacement or small displacement.

Description

technical field [0001] The invention relates to a hydraulic pump starting device and method, in particular to a variable hydraulic pump no-load starting device and method, belonging to the field of fluid transmission and control. Background technique [0002] The hydraulic pump is an essential energy device for the hydraulic system, which provides oil with pressure energy for the hydraulic system. During the working process, in order not to damage the hydraulic pump and the power unit driving the hydraulic pump, the hydraulic pump must be started and operated under no-load conditions, that is, the starting torque of the hydraulic pump is very small. Usually, the no-load start of the hydraulic pump is: when starting, the output oil of the hydraulic pump directly flows back to the oil tank through the action of hydraulic components such as electromagnetic overflow valve, electromagnetic directional valve, and electro-hydraulic directional valve, and the output oil hydraulic pr...

AI Technical Summary

Problems solved by technology

Usually, the no-load start of the hydraulic pump is: when starting, the output oil of the hydraulic pump directly flows back to the oil tank through the action of hydraulic components such as electromagnetic overflow valve, electromagnetic directional valve, and electro-hydraulic directional valve, and the output oil hydraulic pressure The force is close to zero, that is, the hydraulic pump is working in an unloaded state, but when the flow rate of the hydraulic pump output oil is relatively large and the diameter of the hydraulic component that plays the role of unloading is small, the oil output by the hydraulic pump is under pressure. In this way, there will be power loss on the unloaded hydraulic components; to be suitable for the no-load start of a large flow hydraulic pump, it is necessary to use a hydraulic component with a large diameter or a cartridge valve structure as the unloading component. In this way, the size of the unloading device , increased volume, complex structure

[0003] In the existing technology, the no-load start of the hydraulic pump is realized through the unloading effect of the hydraulic components, and the hydraulic pump will output at full flow. In the hydraulic system, there will be a sudden change in the working pressure and flow, which will cause a large pressure shock in the hydraulic system, which will have a damaging effect on the hydraulic pump, hydraulic system and working devices.

Images